Shaft mountings for pulleys, sheaves and the like

ABSTRACT

A shaft mounting having a sleeve which fits over the shaft and which has a tapered external surface engageable within a hub portion of the part to be secured to the shaft, and an annular element which is engageable externally over the hub portion, the sleeve and annular element being movable axially towards one another by tightening of screws engaged therewith to fasten the hub to the shaft.

United States Patent Inventor Walter Frauds Kmum Natalia Ave,lluntingdale, Victoria, Australia Appl. No. 862,404 Filed Sept. 30, 1969Patented Aug. 3, 1971 Priority Oct. 3, 1968 Australia 285/68 SHAFTMOUNTINGS FOR PUILLEYS, SlHllEAl/IES AND THE LIKE 5 Claims, 3 DrawingFigs.

U.S. 1C1 287/5206 Int. Cl F166 1/06 Field 01 Search 287/5206, 52.04, 52;74/2304, 2303 References Cited UNITED STATES PATENTS 827,346 7/1906 Bubb287/52 UK Reeves 74/2303 Breslow 287/5 2.06 Whitaker. 287/5206 Houclt287/5206 Johnson 287/5206 Renner 287/5204 X Firth 287/5206 X PrimaryExaminer David .1. Williamowsky Assistant ExaminerAndrew V. KundratAttorney-Burns, Lobato 8i Zelnick ABSTRACT: A shaft mounting having asleeve which fits over the shaft and which has a tapered externalsurface engageable within a hub portion of the part to be secured to theshaft, and an annular element which 1 is engageable externally over thehub portion, the sleeve and annular element being movable axiallytowards one another by tightening of screws engaged therewith to fastenthe hub to the shaft.

PATENTEU AUG 3 l9?! n7 bs SHAFT MOUNTINGS FOR lPlULlLlEY-S, SIrlIlEA'ltIES AND 'llllillE lLlIliflE FIELD OF THE INVENTION This inventionrelates to the mounting of pulleys, sheaves, gears, sprockets, discs andthe like on shafts.

More particularly the invention relates to mountings of the type inwhich a tapered sleeve is fitted into a tapered bore in the pulley orthe like and is drawn, by operation of a number of screws into firmengagement with the bore so as to be contracted onto a shaft. In onecommon form of mounting of this type, the sleeve is longitudinally splitand is provided with a flange which is drilled to receive the screws andthe screws engage tapped holes in the body of the pulley or the like.With this arrangement the screws exert considerable forces on the bodyin a region which is subject to stress concentration. The region of thebody provided with the tapped holes must therefore be quite thick towithstand these forces and in many cases this is inconvenient. Forexample, wide belt pulleys conventionally comprise a tubular rim and twoannular end discs. If the conventional mounting is employed, the screwsmust be fitted to tapped holes in the end discs around their innerperipheries. Because of the forces imparted by the screws, the end discsmust be formed from very thick plate or be locally thickened, forexample by forging. The present invention provides a mounting whichenables quite thin end discs to be employed with consequent saving inmaterial.

In accordance with the invention means are provided for mounting a discor the like on a shaft, so that the disc will rotate with the shaftwithout being subjected to mounting stresses. The mounting meanscomprises a sleeve disposed on the shaft and having an outer surfacewhich is axially tapered. The disc is provided with an axially locatedintegral hub-flange having a tapered bore for reception over the taperedsurface of the sleeve. The respective taper angles are the same andthereby provide for engagement between the hub-flange and sleeve alongthe entire surface of the bore in the hub-flange. An annular element isreceived over the outer axially extending portion of the hub-flange forengagement along mutually tapered surfaces, and fastening means, such asscrews, are connected between the sleeve and annular element for drawingthe two together. Thus, the fastening means causes relative axialmovement between the hub-flange and sleeve, and between the hub-flangeand annular element, thereby aligning them on the shaft and securingthem so that the hub-flange is substantially free of any axial stress.

A pulley comprising a generally tubular rim and a pair of annular enddiscs may be provided with a pair of mountings according to theinvention. The hubs of these mountings may be in the form of flangeslocated at the inner peripheries of the annular end discs.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may bemore fully explained two specific embodiments thereof will now bedescribed with reference to the accompanying drawings in which:

FIG. l is a longitudinal section through part ofa pulley having a pairof shaft mountings in accordance with the invention;

FIG. 2 is an exploded view corresponding to FlG. l and showing parts ofthe shaft mounting of HG. i disassembled; and

FIG. 3 is a longitudinal section through part ofa pulley having shaftmountings of an alternative construction in accordance with theinvention.

DESCRIPTION OF PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate part of apulley which comprises a rolled plate rim and two annular end discs. Thefigures show part of the cylindrical rim 3 and one of the end discs 4;.End disc 4 is formed from metal plate and at its inner periphery a hubflange 6, which may be formed by a hot pressing technique, projectsinwardly of the pulley.

The inner periphery 7 and the outer periphery 8 of hubflange 6 are bothmachined to a 4 taper, with both surfaces tapering inwardly to the rightas seen in FIG. l.

A longitudinally split sleeve 9 having a split end flange 11 has atapered external surface 12 to fit the bore of hub-flange 6. Flange 11has circumferentially spaced holes T3 to receive screws 14 which alsoproject through holes 16 in end disc 4 to engage tapered holes in anannular ring 17 which locates on the outer peripheral surface 8 ofhub-flange 6, the inner periphery of ring 117 being machined to a taperto suit the taper of the outer peripheral surface of the hub-flange.Screws M are necked at 15 to avoid stretching of their threaded ends.Resiliently compressible corrugated washers T8 are fitted between theheads of screws 14 and flange ll of sleeve 9.

Tightening of screws 1d draws ring 17 to the left and sleeve 9 to theright. This causes a wedging action between the inner periphery of ring17 and the outer periphery of hub-flange 6 and also between the innerperiphery of the hub-flange and the outer periphery of sleeve 9 suchthat the hub-flange is firmly gripped between ring 17 and sleeve 9 andthe sleeve is wedged inwardly so that it contracts and can thereby gripa shaft inserted therethrough. It will be appreciated that tightening ofscrews 14 does not generate large forces in end disc 4, the only forcesexerted on the pulley body being generally equal and oppositecompressive forces on hubflange 6.

The resiliently deformable washers 18 are chosen so that when they arecompressed there is a predetermined axial tension in screws M generatinga required clamping force on sleeve 9.

FIG. 3 shows a modified form of mounting which is particularly suitablein cases where the pulley is required to withstand large forces since itdoes not require any drilling of the pulley body. In this case, the enddisc 21 of the pulley is formed with a hub-flange 22 as before. However,in this case the annular ring 23 has an inwardly directed end flange 24which is provided with the tapped holes to receive the screws. Thelongitudinally split outer sleeve 26 is not provided with an end flangebut is thickened so that it can be drilled with holes to receive thelongitudinal clamping screws 27. As before the tightening of theclamping screws draws the annular ring to the left and thelongitudinally split sleeve to the right so that the hubflange is firmlygripped between them and the longitudinally split sleeve is wedgedinwardly.

It is important to note that, in both described embodiments, thehub-flange is gripped by oppositely directed movements of the sleeve (9or 26) and annular ring (17 or 24) and these movements are effected byforces applied between these parts (by the tightening of bolts 1d or 27)rather than by forces applied directly to the hub, as in the priorarrangements. The parts '9, T7 or 24, 26, being free to move axially ofthe shaft relatively to the hub, merely assume differentially varyingaxial positions during tightening and so impose little, if any, stresson the hub. As a result of this, stress concentration in the hub isminimal. Also, since there is no substantial tendency for axialmovements of the parts 9, 17 or 24, 26 to be transferred to the hubduring tightening, accurate axial positioning of the hub is facilitated.

The above-described embodiments of the invention have been advanced byway of example only and many modifications and variations may be madethereto. For example, in order to save the cost of machining, the outerperiphery of the hub-flange may be left unmachined and the innerperiphery of the ring merely serrated so that it will bite into thehubflange and provide the necessary gripping action. The longitudinallysplit metal sleeve could be replaced by a nonsplit deformable sleeve.Such a sleeve could, for example be constructed of a plastics material.The mountings can also be adapted to suit other types of pulleys,sheaves, gears, discs and the like. For example, in the case of a pulleyor gear having a single central web, a single mounting could be disposedat the inner periphery of that web. It is accordingly to be understoodthat the invention is in no way limited to the details of theillustrated constructions but includes many variations within the scopeof the appended claims.

Iclaim:

1. Means for mounting an integral disc and hub-flange combination on ashaft, comprising a sleeve, and means for fixing said sleeve on a shaft,said sleeve having an axially tapered outer surface, an annular dischaving an integral hub-flange disposed centrally of the inner peripherythereof, said hub-flange having an axially tapered outer surface, andhaving an axially tapered bore which is received over said tapered outersurface of said sleeve, an annular element having a bore which isaxially tapered in the same direction as the bore of said hub-flange andwhich is received over said axially tapered outer surface of saidhub-flange and spaced axially from said integral disc in assembledposition, said integral disc extending radially outward beyond the outerperipheries of said sleeve and annular element, and fastening meansengaging only said sleeve and annular element for concurrently holdingsaid tapered bore of said annular element in engagement with said outersurface of said hub-flange, and for holding said tapered bore of saidhub-flange in engagement with said outer surface of said sleeve, wherebysaid hub-flange is axially aligned with respect to said shaft and heldfor rotation therewith, 2. Means for mounting an integral disc andhub-flange combination on a shaft as set forth in claim 1, in which saidmeans for fixing said sleeve on a shaft comprises a split in saidsleeve,

whereby said fastening means causes compression of said split sleeveagainst said shaft due to said engagement between said hub-flange andsleeve.

3. Means for mounting an integral disc and hub-flange combination on ashaft as set forth in claim 1, in which said fastening means comprises aplurality of screws, said annular element has a flange extendingradially inward and having a plurality of axially disposed openingstherein, and said sleeve has a plurality of openings aligned with theopenings in said annular element flange, wherein said screws arereceived respectively in said aligned openings for drawing together saidsleeve and annular element.

4. Means for mounting an integral disc and hub-flange combination on ashaft as set forth in claim 1, in which said fastening means comprises aplurality of screws, said sleeve has a flange extending radially outwardand having a plurality ofaxially disposed openings therein, and saidannular element has a plurality of openings aligned with the openings insaid sleeve flange, wherein said screws are received respectively insaid aligned openings for drawing together said sleeve and annularelement.

5. Means for mounting an integral disc and hub-flange combination on ashaft as set forth in claim 1, in which the tapers of said bores andsaid respective outer surfaces of said sleeve and hub-flange aresubstantially the same.

1. Means for mounting an integral disc and hub-flange combination on ashaft, comprising a sleeve, and means for fixing said sleeve on a shaft,said sleeve having an axially tapered outer surface, an annular dischaving an integral hub-flange disposed centrally of the inner peripherythereof, said hub-flange having an axially tapered outer surface, andhaving an axially tapered bore which is received over said tapered outersurface of said sleeve, an annular element having a bore which isaxially tapered in the same direction as the bore of said hub-flange andwhich is received over said axially tapered outer surface of saidhubflange and spaced axially from said integral disc in assembledposition, said integral disc extending radially outward beyond the outerperipheries of said sleeve and annular element, and fastening meansengaging only said sleeve and annular element for concurrently holdingsaid tapered bore of said annular element in engagement with said outersurface of said hubflange, and for holding said tapered bore of saidhub-flange in engagement with said outer surface of said sleeve, wherebysaid hub-flange is axially aligned with respect to said shaft and heldfor rotation therewith.
 2. Means for mounting an integral disc andhub-flange combination on a shaft as set forth in claim 1, in which saidmeans for fixing said sleeve on a shaft comprises a split in saidsleeve, whereby said fastening means causes compression of said splitsleeve against said shaft due to said engagement between said hub-flangeand sleeve.
 3. Means for mounting an integral disc and hub-flangecombination on a shaft as set forth in claim 1, in which said fasteningmeans comprises a plurality of screws, said annular element has a flangeextending radially inward and having a plurality of axially disposedopenings therein, and said sleeve has a plurality of openings alignedwith the openings in said annular element flange, wherein said screwsare received respectively in said aligned openings for drawing togethersaid sleeve and annular element.
 4. Means for mounting an integral discand hub-flange combination on a shaft as set forth in claim 1, in whichsaid fastening means comprises a plurality of screws, said sleeve has aflange extending radially outward and having a plurality of axiallydisposed openings therein, and said annular element has a plurality ofopenings aligned with the openings in said sleeve flange, wherein saidscrews are received respectively in said aligned openings for drawingtogether said sleeve and annular element.
 5. Means for mounting anintegral disc and hub-flange combination on a shaft as sEt forth inclaim 1, in which the tapers of said bores and said respective outersurfaces of said sleeve and hub-flange are substantially the same.